Results were also obtained in three cancer cell lines transfected with an HIF-1 reporter plasmid containing a hypoxia response element that mediates HIF-1-dependent gene transcription, with all the alkaloids (13–19) proving to significantly decrease the transcriptional activity of HIF-1α in human colorectal carcinoma HCT 116 cells, and (−)-discorhabdin B dimer (13) featuring as the most competent [115]. This evidence concerns the gene HIF1A and colorectal carcinoma.